Pump-jack



R. P. BEVAN.

PUMP JACK.

APPLICATION msu JAN.13,1920.

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PATENT OFFICE.

.ROBERT P. BEVAN, OF MINNEAPOLIS, MINNESOTA. A A

PUMP-JACK.

Specification of Letters Patent. Patented Jan. 11, 1921.

A'pplication led January 13, 1920. Serial No. 351,243.

. To all whom t may' concern Be it known that 1,' ROBERT P. BEVAN, a citizen of the United States, and a resident of Minneapolis, in the county of Hennepm and State of Minnesota, have invented certain new and useful., Improvements in Pump-Jacks, of which the following is a specification.

One object of my invention is to provide in a pump jack an improved construction that will allow the best application of the driving power to the pump.

AnotherV object is to provide improved means for inclosing the gearing so that it may be run in oil and free from dirt.

Another object is to provide an improved form of construction whereby the assembly and installation ofthe jack are facilitated.

With these and incidental objects in view, the invention consists of certain novel features of construction and combination of parts, the essential elements of which are hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing, Figure 1 is a side elevation of my improved jack as applied to a pump; Fig. 2 is van enlarged side elevation of the jack with a portion broken away; Fig. 3 is a section taken'on the line 3-3, Fig. 2; and Fig. 4 is a section taken on the line @-4, Fig. 3.

As shown in the drawing, the frame com-v prises a gear housing 1, provided with an internal boss 3 and an internal boss 4.

The interior of the housing is fashioned at 5 into aninternal gear, the teeth thereof preferably being cast.

A cover plate 6 is provided for the housing, and carries two bosses 7 and 8. A stub shaft` 9 is driven into the boss 3 and permanently located therein, and is journaled in the boss 7 and the set collar -10 prevents the separation of the cover from the housing.

The pulley shaft 11, journaled in the boss 8 is driven by the pulley 12 and drives the pinion 13 co-acting with the internal gear 5, so the rotation of the pulley 12 rotates the gear housingl on the stub shaft 9 rotating in the boss 7.

The cover plate is provided with three depending legs 14, 15, and 16, which support the jack on its foundation.

A boss 17l carried by the cover plate 6 has' driven therein a stub shaft 18 on which the Walking beam 19 is journaled at 20, a set collar 21 locating the Walking beam on the shaft.

The walking beam is slotted out at 22 and the roller 23 journaled on the shaft 24 carried by the boss 4 reciprocates in thc slot 22. The opposite end of the Walking beam is forked at 25 and is fashioned to receive the pump links 26 adapted to be connected with the plunger 27 of the pump 28 to which the jack' is applied.

It is apparent that when the power pulley is driven by any suitable means the forked end of the walking beam will move up and down, and that the up stroke will be made when the roller 23 is driven from approximately point 29 to the point 30, Fig. 2, and that the down stroke will be made when the roller 23 is traveling from the point31 to. the point 32, thereby giving a slow upward motion with a long leverage, and a quick downward or return motion with a short leverage.

With the construction as shown, it is possible to place the pulley on the opposite end of the jack from the pump and obtain the desired ratio in lifting and return stroke, an object that is much desired in'pump jacks, as it allows the placing of the jack in best relation to practically any type of pump.

While I have described my invention and illustrated it in one particular design, I do not wish itunderstood that I limit myself to this construction, as it is evident that the application of the invention may be varied in many ways within the scope ofthe folllowing claims.

Claims:

1. In a pump jack the combination of a gear housing having its inner perimeter fashioned into an internal gear, a boss centrally positioned with respect to said internal gear, a stub shaft carried by said boss, a cover plate journaled on said stub shaft, having its face closely litted against the open side Aof said housing, a boss carried by said plate, a4 pulley shaft journaled in said boss, a driving pulley for said shaft, a pinion driven bysaid shaft, and coacting with said internal gear, a shaft fixed in 'said housing and extending at right angles to the plane of said internal gear, a boss carried by said cover, a shaft fixed in said boss and extending parallel to said last named shaft, a walking beam journaled on'the shaft carried by i ne* said cover plate boss and having a groove at one end thereof in which said shaft extending from the external boss of said housing reciprocates, and means carried by the other ind( of the Walking beam to attach to pump in s.

2. In a pump jack the combination of a cover plate formmg the frame of the jack, an internal gear associated with said cover plate, a stub shaft carried by said cover plate and journaledtherein and centrally eld in said gear, a drive shaft journaled in said cover plate, ,a drive pinion driven by said shaft and coacting with said gear, a stub shaft projecting exteriorly from said internal gear and at right angles to the plane thereof, a Walkin beam mounted for oscillating motion with respect to said cover plate frame and having a groove at one end thereof,'said groove coacting with the stub shaft projecting from said gear.

3. In a pump iack the combination with a cover late forming the frame of the jack, of an internal gear, a pinion coacting with Said gear and positioned to one side of the center of said gear, a walking beam mounted for oscillation in respect to said cover plate and having its center of oscillation oppositely disposed with respect to the center of said gear from said pinion, and means carried by said gear for oscillating said walking beam, the end of said walking beam oposite from the end coacting with said gear eing forked and having means at the forked extremity thereof for attachment to pump links.

ROBERT P. BEvAN. 

